It has been demonstrated that CD8+ cytotoxic T lymphocytes (CTLs) recognize epitope peptides derived from tumor-associated antigens (TAAs) presented on MHC class I molecules, and subsequently lyse the tumor cells. Since the discovery of the MAGE family as the first example of TAAs, many other TAAs have been discovered using immunological approaches (Boon T. (1993) Int J Cancer 54: 177-80.; Boon T. et al., (1996) J Exp Med 183: 725-9.; van der Bruggen P et al., (1991) Science 254: 1643-7.; Brichard V et al., (1993) J Exp Med 178: 489-95.; Kawakami Y et al., (1994) J Exp Med 180: 347-52.). Some of them are now in clinical development as targets of immunotherapy. TAAs discovered to date include MAGE (van der Bruggen P et al., (1991) Science 254: 1643-7.), gp100 (Kawakami Y et al., (1994) J Exp Med 180: 347-52.), SART (Shichijo S et al., (1998) J Exp Med 187:277-88.), and NY-ESO-1 (Chen Y. T. et al., (1997) Proc. Natl. Acd. Sci. USA, 94: 1914-8.). On the other hand, certain gene products demonstrated to be somewhat specifically over-expressed in tumor cells have been shown to be recognized as targets for inducing cellular immune responses. Such gene products include p53 (Umano Y et al., (2001) Br J Cancer, 84:1052-7.), HER2/neu (Tanaka H et al., (2001) Br J Cancer, 84: 94-9.), CEA (Nukaya I et al., (1999) Int. J. Cancer 80, 92-7.) and the like.
Despite significant progress in basic and clinical research concerning TAAs (Rosenberg S A et al., (1998) Nature Med, 4: 321-7.; Mukherji B. et al., (1995) Proc Natl Acad Sci USA, 92: 8078-82.: Hu X et al., (1996) Cancer Res, 56: 2479-83.), only a very limited number of candidate TAAs suitable for treatment of cancers are presently available. TAAs that are abundantly expressed in cancer cells, and whose expression is restricted to cancer cells, would be promising candidates as immunotherapeutic targets.
Both HLA-A24 and HLA-A0201 are common HLA alleles in the Japanese and Caucasian populations (Date Y et al., (1996) Tissue Antigens 47: 93-101.; Kondo A et al., (1995) J Immunol 155: 4307-12.; Kubo R T et al., (1994) J Immunol 152: 3913-24.; Imanishi et al., Proceeding of the eleventh International Histocompatibility Workshop and Conference Oxford University Press, Oxford, 1065 (1992); Williams F et al., (1997) Tissue Antigen 49: 129-33.). Thus, antigenic peptides of cancers presented by these HLA alleles may find particular utility in the treatment of cancers among Japanese and Caucasian patients. Further, it is known that the induction of low-affinity CTL in vitro usually results from exposure to high concentrations of peptides, generating a high level of specific peptide/MHC complexes on antigen-presenting cells (APCs), which will effectively activate these CTL (Alexander-Miller et al., (1996) Proc Natl Acad Sci USA 93: 4102-7.).
Recently, HLA class I-binding peptide sequence can be expected using algorithms (Journal of Immunological Methods, (1995), Vol. 185, pp. 181-190, J. Immunol., (1994), Vol. 152, pp. 163-175, protein science, (2000), Vol. 9, pp. 1838-1846). However, it is hard to say that the expected epitope peptide can be cut to the size and expressed on the target cell surface with HLA molecule and recognized by CTL. Moreover, the algorithm, for example BIMAS (http://bimas.dcrt.nih.gov/cgi-bin/molbio/ken_parker_comboform) (Parker K C, et al., (1994) J Immunol.; 152(1):163-75.; Kuzushima K, et al., (2001) Blood.; 98(6):1872-81.)) can suggest the HLA molecule-binding peptide, but the suggested peptide is not so rigorous (Bachinsky M M, et. al., Cancer Immun. 2005 Mar. 22; 5:6.). Thus TAA screening still remains a lot of challenges and difficulties.
Recent developments in cDNA microarray technologies have enabled the construction of comprehensive profiles of gene expression in malignant cells as compared to normal cells (Okabe, H. et al., (2001) Cancer Res., 61, 2129-37.; Lin Y M. et al., (2002) Oncogene, 21; 4120-8.; Hasegawa S. et al., (2002) Cancer Res 62:7012-7.). This approach enables a more thorough understanding of the complex nature of cancer cells and the mechanisms of carcinogenesis and facilitates the identification of genes whose expression is deregulated in tumors (Bienz M. et al., (2000) Cell 103, 311-20.). Among the transcripts identified as up-regulated in cancers, CDH3 (GenBank Accession No. NM—001793; SEQ ID Nos.1, 2), EPHA4 (GenBank Accession No. L36645; SEQ ID Nos.3, 4), ECT2 (GenBank Accession No. AY376439; SEQ ID Nos.5, 6), HIG2 (GenBank Accession No. NM—013332; SEQ ID Nos.7, 8) INHBB (GenBank Accession No. NM—002193; SEQ ID Nos.9, 435, 10, 436), KIF20A (GenBank Accession No. NM—005733; SEQ ID Nos.11, 12), KNTC2 (GenBank Accession No. AF017790; SEQ ID Nos.13, 14), TTK (GenBank Accession No. NM—003318; SEQ ID Nos.15, 16) and URLC10 (GenBank Accession No. NM—017527; SEQ ID Nos.17, 18) have been recently discovered. The entire contents of the references are incorporated by reference herein. These genes are of particular interest to the present inventors, being specifically up-regulated in tumor cells of the various cancer tissues of the cases analyzed (see below). Thus, immunogenic peptides derived from CDH3, EPHA4, ECT2, HIG2, INHBB, KIF20A, KNTC2, TTK and URLC10 may find utility in selectively killing tumor cells that express such antigens. The present invention addresses these and other needs.
Since cytotoxic drugs, such as M-VAC, often cause severe adverse reactions, it is clear that thoughtful selection of novel target molecules on the basis of well-characterized mechanisms of action should be very helpful in the development of effective anti-cancer drugs having a minimized risk of side effects. Toward this goal, expression profile analyses were previously performed on various cancers and normal human tissue. Such studies led to the discovery of multiple genes that are specifically over-expressed in cancer (Lin Y M, et al., Oncogene. 2002 Jun. 13; 21:4120-8.; Kitahara O, et al., Cancer Res. 2001 May 1; 61:3544-9.; Suzuki C, et al., Cancer Res. 2003 Nov. 1; 63:7038-41.; Ashida S, Cancer Res. 2004 Sep. 1; 64:5963-72.; Ochi K, et al., Int J Oncol. 2004 March; 24(3):647-55.; Kaneta Y, et al., Int J Oncol. 2003 September; 23:681-91.; Obama K, Hepatology. 2005 June; 41:1339-48.; Kato T, et al., Cancer Res. 2005 Jul. 1; 65:5638-46.; Kitahara O, et al., Neoplasia. 2002 July-August; 4:295-303.; Saito-Hisaminato A et al., DNA Res 2002, 9: 35-45.). Examples of such genes identified as over-expressed in various cancers include, but are not limited to, CDH3, EPHA4, ECT2, HIG2, INHBB, KIF20A, KNTC2, TTK and URLC10. CDH3 has been previously identified as over-expressed in bladder cancer, cervical cancer, cholangiocellular carcinoma, colorectal cancer, endometriosis, gastric cancer, diffuse-type gastric cancer, non-small cell lung cancer (NSCLC), pancreatic cancer, soft tissue tumor and testicular tumor. EPHA4 has been identified in bladder cancer, cervical cancer, cholangiocellular carcinoma, endometriosis, diffuse-type gastric cancer, ovarian cancer, pancreatic cancer, prostate cancer and soft tissue tumor. ECT2 has been identified in bladder cancer, breast cancer, cervical cancer, cholangiocellular carcinoma, chronic myeloid leukemia (CML), colorectal cancer, esophageal cancer, NSCLC, lymphoma, prostate cancer, renal carcinoma and small cell lung cancer (SCLC). HIG2 has been identified in renal carcinoma and SCLC. INHBB has been identified in cholangiocellular carcinoma, esophageal cancer, NSCLC, renal carcinoma, SCLC and soft tissue tumor. KIF20A has been identified in bladder cancer, breast cancer, cholangiocellular carcinoma, esophageal cancer, NSCLC, pancreatic cancer, prostate cancer, renal carcinoma and SCLC. KNTC2 has been identified in bladder cancer, breast cancer, cervical cancer, cholangiocellular carcinoma, CML, colorectal cancer, esophageal cancer, NSCLC, lymphoma, osteosarcoma, ovarian cancer, pancreatic cancer, prostate cancer, renal carcinoma, SCLC and soft tissue tumor. TTK has been identified in bladder cancer, breast cancer, cervical cancer, cholangiocellular carcinoma, CML, colorectal cancer, esophageal cancer, liver cancer, NSCLC, lymphoma, osteosarcoma, prostate cancer, SCLC and soft tissue tumor. URLC10 has been identified in bladder cancer, cervical cancer, cholangiocellular carcinoma, esophageal cancer, gastric cancer, NSCLC, osteosarcoma, pancreatic cancer and SCLC.